Sean S.-Y. Lin, Su Ha, and William J. Thomson. School of Chemical Engineering and Bioengineering, Washington State University, PO Box 642710, Pullman, WA 99164-2710
Two supported molybdenum carbide catalysts, Mo2C supported on γ-alumina (Mo2C/γ-Al2O3) and zirconia (Mo2C/ZrO2), were investigated as an alternative catalyst for steam reforming of methanol. The catalysts were prepared by a temperature-programmed reaction (TPR) method, and it was found that the supported Mo2C catalysts are superior to an unsupported catalyst, with Mo2C/ZrO2 having a higher hydrogen yield than Mo2C/γ-Al2O3. It is hypothesized that the zirconia support plays a synergistic role during methanol steam reforming, probably by altering the reaction pathway. The suppression of methanation and the promotion of the water-gas shift (WGS) reaction by the interaction between molybdenum carbide and the zirconia support resulted in the increased hydrogen yield. The optimum operating conditions were observed at a steam-to-carbon ratio of one and 400 oC. At these conditions, the reforming activity remained stable for longer than ten hours.